What 5S is and how to implement it step by step

In one line

5S is a 5-stage method so that a workstation holds only what is necessary, everything has a fixed place, and that condition is sustained over time instead of lasting a week after the audit photo.

What it is

The name comes from five Japanese words that start with S: Seiri, Seiton, Seiso, Seiketsu and Shitsuke. In Spanish they are usually translated as Seleccionar (or Clasificar), Ordenar, Limpiar, Estandarizar and Disciplina (roughly Sort, Set in order, Clean, Standardize and Discipline) — although the INTI guide, written for Argentine plants, uses its own variant for the last two: it calls them Mantenimiento and Autodisciplina (Maintenance and Self-discipline). The content is the same; only the label changes.

INTI insists on a point that tends to get lost: 5S is not "tidying up and cleaning" as a one-day task. It is a program with a designated leader, prior training, a pilot area to test the methodology before scaling it to the whole plant, and an initial audit that serves as a baseline to measure progress afterward.

What it is for in maintenance

In a maintenance area, 5S is not cosmetic: it directly attacks the time lost looking for things and the errors from mixing up similar parts. A disorganized tool crib, a spare parts cabinet with no coding, or a workbench full of items nobody has used in months all create the same problem — maintenance labor time spent searching, not repairing.

There is also a direct link to early failure detection: a clean floor lets you see an oil leak the same day it appears, while an always-dirty floor hides it for weeks. That is why INTI sums up the cleaning stage with a phrase worth highlighting: "more important than cleaning is not making a mess" — cleaning as inspection, not as aesthetics.

How it is applied: the 5 stages

1. Seiri — Sort

You identify what is in the area and separate what is necessary from what is not. INTI documents this with a very concrete tool: the red tag. Each doubtful item (a tool nobody remembers the purpose of, an unidentified box of spare parts, an old motor abandoned in a corner) gets a tag with the item, the reason and the date. A centralized log of red tags lets you track what was decided for each one: dispose of it, sell it or relocate it to another area. The guiding question is simple: is this item necessary, in this quantity, in this place?

2. Seiton — Set in order

With the unnecessary items out, each thing is placed according to how often it is used: what is used every day, closer; what is used occasionally, farther away. INTI recommends assigning a unique code both to the item and to its location (a location register), and using color-coded labels so that anyone — not just the person who organized it — can find something quickly. The underlying idea is the classic one: a place for everything, and everything in its place. In a maintenance tool crib this translates into boards with tool outlines (shadow boards): if the outline is empty, the tool is not where it should be, and you notice at a glance.

3. Seiso — Clean

You remove the dirt and, more importantly, identify its root cause to keep it from coming back (there is no point in cleaning an oil pan if the machine keeps leaking). INTI proposes three tools to sustain it: a cleaning plan (frequency and person responsible for each area), a step-by-step cleaning instruction, and a cleaning log to verify that it was actually done.

4. Seiketsu — Standardize (Maintenance, in INTI's terminology)

The first three S's are turned into routine, not a one-off effort. The central tool is visual control: a 5S board where before/after photos, audit results and progress indicators are posted, visible to the whole team.

5. Shitsuke — Discipline (Self-discipline, in INTI)

This is the stage that sustains (or not) everything before it over time. The ILO/Cinterfor manual sums it up as "respect for rules and agreements" and connects it directly to the periodic audit: it calls the 5S audits "patrols," ideally carried out by someone who does not belong to the audited area, so that the score is impartial. The ILO is explicit in the title of its manual: "sustainable" is the key word — most 5S programs do not fail in the first three S's; they fail because nobody audits or corrects six months later.

INTI documents an audit sheet model with 20 items (4 for each S, in two blocks: workstations and general areas) out of a total of 200 points, and the ILO uses a scale from 0 to 100 with categories from A (91-100, excellent) to E (0-30, unsatisfactory), plotted month by month so that the trend — not the snapshot of a single day — is what gets discussed in the follow-up meetings.

Real example (illustrative)

This example is illustrative, built to show the typical order of magnitude of the impact of 5S in a maintenance tool crib — it does not come from a specific case reported in the cited sources.

A tool crib in a metalworking plant serves 8 mechanics per shift. Before applying 5S: tools are stored with no fixed criteria, there are boxes with obsolete parts mixed with current spare parts, and finding a specific wrench takes 6 to 8 minutes on average — time during which the work order is stopped and the mechanic is too. With 8 mechanics making 3 or 4 searches per shift, that is more than 3 man-hours per shift lost just searching.

After applying red tags (30% of the items in the tool crib are discarded and relocated, turning out to be obsolete or duplicates) and boards with an outline for each tool, search time drops to less than 1 minute for 90% of requests. The tool crib goes from "the mechanic searches" to "the mechanic sees where something is missing before anyone asks for it" — which is, in essence, the goal of the visual control that both INTI and the ILO document.

Benefits

The ILO manual sums up the typical contrast between an area before and after 5S: from low productivity, low quality standards, unnecessary items and tools mixed in, poor inventory control and difficulty locating materials — to visual management, higher productivity, fewer workplace accidents, efficient use of physical space, smoother processes and, a fact that connects directly to SMED, shorter set-up times.

In maintenance specifically:

• Less labor time spent looking for tools, spare parts or technical documentation
• Faster detection of leaks, wear and anomalies, because a clean area makes the abnormal visible
• Fewer errors from mixing up similar parts or tools stored together
• A foundation of order and discipline on which you can later build TPM or a predictive maintenance program — without this foundation, any more sophisticated program degrades just as fast

Limitations to keep in mind

• 5S does not solve a process design problem or a machine reliability problem: it is organizational hygiene, not engineering. Poorly maintained equipment keeps failing the same way even if the tool crib is spotless.
• The stage that fails most is not Seiri, Order or Cleaning — it is Discipline. Without periodic audits ("patrols," in the ILO's words), the order achieved fades within weeks.
• An audit done only to "pass the photo" (cleaning right before the auditor comes by) does not build the habit that 5S is after — the point is that the condition is maintained every day, not on review day.
• Getting started is relatively easy and cheap; sustaining it requires management to assign real time to the audits and act on what they find, not just initial training.

In summary

5S organizes a workstation in five concrete stages — removing the unnecessary with red tags, placing each thing according to its use, cleaning while understanding cleaning as inspection, standardizing with visual control and sustaining everything with periodic audits. The real value in maintenance is not the photo of a tidy tool crib, but the time no longer lost searching and the problems caught earlier because they are visible. And, as the name of the ILO manual itself points out, the word that decides whether the program worked was "sustainable" or not.